Apparatus and method for manufacturing optical disks, apparatus and method for recording data on optical disks, apparatus and method for reproducing data from optical disks, and optical disk

Abstract

Described herewith is an optical disk manufacturing apparatus for reading recorded digital data from an optical disk, comprising an encryption unit ( 22, 23 ) for encrypting entered digital data according to a plurality of key information; an optical disk substrate manufacturing unit 2 for manufacturing an optical disk substrate 4 on which the encrypted digital data and key information are recorded in the form of physical form changes; a reflection film forming unit 41 for forming a reflection film on the optical disk substrate 4 ; and a key information recording unit 7 for recording key information on the optical disk substrate on which the reflection film is formed. The reflection factor of the optical disk is changed locally, thereby giving a jitter to the position information of each pit edge, and desired data is recorded additionally according to this jitter. Pits, etc. are disposed so as to be deviated from the track center towards the inner/outer region of the optical disk 2 , thereby recording such subdata as key information KY, etc.

What is claimed is:  
     
       1. An apparatus for manufacturing an optical disk having recorded digital data to be read out with a laser beam irradiated on said optical disk, comprising: 
       encrypting means for encrypting input digital data according to a plurality of key information;  
       optical disk substrate manufacturing means for manufacturing an optical disk substrate on which said encrypted digital data and said key information are recorded in the form of physical configurational change;  
       reflection film forming means for forming a reflection film on said optical disk substrate; and  
       key information recording means for recording said key information on said optical disk substrate having said reflection film thereon in the form of a reflectance change.  
     
     
       2. An optical disk manufacturing apparatus in accordance with  claim 1 , wherein said optical disk substrate manufacturing means comprises: 
       exposing means for converging a laser beam on a master optical disk according to said encrypted digital data and said key information, thereby exposing said optical master disk;  
       stamper forming means for forming a stamper by applying a chemical treatment on said exposed optical master disk, thereby changing the physical configuration thereof; and  
       duplicating means for transferring said physical configurational change on said stamper, thereby generating a plurality of optical disk substrates.  
     
     
       3. An optical disk manufacturing apparatus in accordance with  claim 2 , wherein said exposing means comprises: 
       laser beam intensity modulating means for modulating the intensity of said laser beam according to said encrypted digital data; and  
       laser beam convergent position changing means for changing the convergent position of said laser beam according to said key information.  
     
     
       4. An optical disk manufacturing apparatus in accordance with  claim 3 , wherein said laser beam intensity changing means comprises: 
       modulating means for generating a modulated signal according to said encrypted digital data; and  
       optical modulating means for controlling the on/off of said laser beam according to said modulated signal.  
     
     
       5. An optical disk manufacturing apparatus in accordance with  claim 1 , wherein said key information recording means comprises: 
       laser beam generating means for generating a laser beam;  
       optical intensity modulating means for modulating said laser beam according to said key information; and  
       converging means for converging and irradiating said modulated laser beam at a predetermined position on said optical disk.  
     
     
       6. A method for manufacturing an optical disk having recorded digital data to be read out with a laser beam irradiated thereon, comprising: 
       an encrypting step for encrypting input digital data according to a plurality of key information;  
       an optical disk substrate manufacturing step for manufacturing an optical disk substrate on which said encrypted digital data and said key information are recorded in the form of physical configurational change;  
       a reflection film forming step for forming a reflection film on said optical disk substrate; and  
       a key information recording step for recording said key information on said optical disk substrate on which said reflection film is formed in the form of a reflectance change.  
     
     
       7. An optical disk manufacturing method in accordance with  claim 6 , wherein said optical disk substrate manufacturing step comprises: 
       an exposing step for converging a laser beam on an optical disk according to said encrypted digital data and said key information, thereby exposing said optical master disk;  
       a stamper forming step for forming a stamper by applying a chemical treatment on said exposed optical master disk, thereby changing the physical configuration thereof; and  
       a duplicating step for transferring the physical configurational change on said stamper, thereby generating a plurality of optical disk substrates.  
     
     
       8. An optical disk manufacturing method in accordance with  claim 6 , wherein said key information recording step comprises: 
       a laser generating step for generating a laser beam;  
       a modulating step for modulating said laser beam according to said key information; and  
       a laser irradiating step for converging and irradiating said laser beam on said optical disk substrate.  
     
     
       9. An optical disk having digital data recorded in the form of physical configurational change so as to be reproduced with a laser beam irradiated on and reflected from a reflection film, 
       wherein said digital signal is encrypted with the use of a plurality of key information,  
       one of said plurality of key information is recorded on said optical disk in the form of physical configurational change, and  
       at least one of said plurality of key information is recorded in the form of reflectance change of said reflection film on said optical disk.  
     
     
       10. A method for reproducing an optical disk having recorded encrypted digital data, comprising: 
       first reproducing step for reproducing first key information recorded on said optical disk in the form of physical configurational change;  
       second reproducing step for reproducing second key information recorded on said optical disk in the form of reflectance change; and  
       an encrypting step for reproducing the digital data recorded on said optical disk and decrypting said reproduced digital data with the use of said first and second key information.